docs: def _filter_candidates(self, tokens, candidates):
          """Discard if long shorter than abbr, or if abbr token(s) are in the long token(s)."""
          results = []
          for abbr_span, long_span in candidates:
              abbr = tokens[abbr_span[0]:abbr_span[1]]
              long = tokens[long_span[0]:long_span[1]]
              if not all(a in long for a in abbr) and len(''.join(long)) > len(''.join(abbr)):
                  results.append((abbr_span, long_span))
          return results